Sorry to revive an old topic, but I am having the same problem. I want to remove this rock (and maybe return it later when it's clean) that has over 50 polyps of green palys (2 different kinds, no other coral on it) and it is impossible to remove them manually all at once mostly with the rock still in the tank. Once I tried to pull some that were growing on the back glass but they didn't get out and were releasing some sort of a green goo which scared me and I gave up. I thought about placing the rock in a bucket with fresh water (or with some kalk added) but I'm afraid that they can release something anyway and contaminate the bucket making it unusable forever. Can the palytoxin be neutralized after some time, like letting the polyps dry and die just letting the rock outside the tank? It's not my favourite option though. I could try removing them all with tweezers or scissors but that green goo scared me and I can't tell if it will be dangerous if it's released with the cutting when and if I return the rock to the tank. I thought also about bleaching the rock with the polyps still there, but I have no idea if this will also release the toxins.